For the course we built a Top Lit Up Draft (TLUD) stove out of an old propane tank. There was a silver fire TLUD stove we have been using to cook on during the PDC. it used a surprisingly small amount of wood to be able to boil water ( I did send in from Amazon in a pot skirted pot that worked great) and cook. It probably used a 10th of the wood the rocket stoves around there used for the same cooking.
To start with I beat the safety cage and valve off an old tank. Then filled it with gray water to make sure all the gas was out before we started cutting on it. I traced the outline of the stove pipe on the top of the tank. Then using the permi builder tool of choice, the angle grinder with a cut off wheel, we cut the top out just to fit the stove pipe. The theory is just below that lip inside you have holes in the pipe five times the number as you do at the bottom of the stove pipe inside the tank. Sara and I drilled five evenly space holes at the bottom and then tried to evenly space 25 holes around the top. Anybody that's ever drilled in sheet metal can tell you how fun that is. We did it on the drillpress and I took a block of wood and put it inside the pipe lined it up and Sarah, as she did everything, very enthusiastically drilled the holes. I then calculated the total area of the 30 holes And Sarah cut vent at the bottom of the tank equal to that area. We made a couple castle notches at the top where a pot sets for the fire to go around.
To use it you stack wood in it, I always did it vertically, and start the fire on top of the wood. The fire runs down the wood the first time burning off the volatiles and wood gases. When it burns all way to the bottom of the flame will change color to blue and start burning back up, burning the charcoal it has made. If you want biochar for a filter, to pee on for soil improvement, or just plain charcoal, once it starts burning blue flames, you tip it out and douse it.
How does the commercial version compare to the homemade one?
Location: Huntsville, United States
posted 3 years ago
It was one of the last things we built at the AT so did not use it that much or did a formal study on it. Most of the cooking we did at the end of the AT were bigger group meals that we did in Tim's Rocket Oven with side grill.
I think Josh fried eggs on it a couple of times which it did fine with. Definitely for the price differential I did not see much difference. I think that Silver Fire (with out the fan) which is very nice but it costs like $200. We might have had $10 worth of material in the one we built.
Like I noted above a big pro is both homemade and the Silver Fire cooked more than any of the brick Rocket Stoves for the same amount of wood.
The cons (for both) are if you need to cook longer than the initial load of wood would do, it was hard to add wood to keep the same level of heat going. On an initial load the Silver Fire would easily boil that whole pot of water and still cook eggs after, I would think the homemade one would do the same. But if all you wanted to do was fry eggs the initial load was way overkill, but still would have been a lot less wood than if you tried it on a brick/mortar Rocket Stove with a skillet or Tim's Rocket Stove Grill. I know the Rocket Stoves are supposed to be the be all end all, but I was surprised at how much wood they took to heat up and go. Still probably better than a campfire but the brick Rocket Stoves seamed inefficient for cooking small meals.
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